Plastics pipes are widely employed in the fluid distribution networks of, for example, the gas and water industries and in irrigation and sewage treatment. In addition, the telecommunications and electricity industries are increasingly deploying plastics pipes as ducting for cables. A widespread use of plastics pipes is in domestic heating systems, in particular for hot water pipes, and especially for under-floor heating. In the installation of these pipe networks there is frequently a need to position or anchor lengths of plastics pipe on a support, to obtain an even heating within the room or building.
A wide range of fastening devices and systems are available for positioning or anchoring a plastics pipe on a support. Typically these consist of brackets or other fastening means that encircle the pipe and can be fixed to the support by screws, bolts, or other fasteners. Whilst such devices can work well in practice, they are dependent on having a support that is suitable for receiving the screws or bolts, have parts that are easily mislaid and inevitably are time-consuming to install.
Where the supporting surface is too soft, too hard, or insufficiently rigid, for the use of screws or bolts, other techniques must be employed. For example, in the installation of pipe networks for underfloor heating, an insulating layer of expanded polystyrene (EPS) boards is first laid down to form a supporting surface. A serpentine network of plastics pipes is then laid in position on the EPS surface and a layer of concrete poured over the network to cover the pipe network and complete the installation. During the assembly of the network and pouring of the concrete it is essential that the individual plastics pipes are anchored so that they do not move from their assigned positions. To this end it is known to provide EPS boards with spaced apart integrally moulded upstanding posts that define the positions of the plastics pipes in the network. However this system is somewhat inflexible, in that the posts cannot be moved once the EPS boards have been laid in position, for example, where it is necessary to make small adjustments in the position or orientation of the pipes.
Hook and loop type separable fasteners are well known and are used to join two members detachably to each other. These types of fasteners generally have two components disposed on opposing member surfaces. One component typically includes a plurality of resilient hooks while the other component typically includes a plurality of loops. When the two components are pressed together they interlock to form a releasable engagement. In this specification, such components are termed “inter-engageable”. The resulting joint created by the releasable engagement is relatively resistant to shear and pull forces and weak in peel strength forces. As such, peeling one component from the other component can be used to separate the components with a minimal applied force. As used herein, the term “shear” refers to an action or stress resulting from applied forces that causes or tends to cause two contiguous parts of a body to slide relatively to each other in a direction parallel to their plane of contact. The term “pull force” refers to an action or stress resulting from applied forces that causes or tends to cause two contiguous parts of a body to move relatively to each other in a direction perpendicular to their plane of contact. Hook and loop fasteners can, for example, comprise mating strips or patches of filamentary stress-bearing hooks and loops.
As described in U.S. Pat. No. 5,656,351, monofilament or multifilament loops are knit or woven into a textile backing, or ground, to form the loop component of the fastener. To form the hook component, monofilament loops are woven in the same manner, then passed through a hook cutting process in which portions of the monofilament loops are cut away to form hooks.
In an alternative method, as described in U.S. Pat. No. 6,660,121, fastener elements integral with a base web are moulded continuously from a flowable resin, by providing a cylindrical mould roll rotatable about an axis of rotation and defining an array of fastener element-shaped mould cavities in a peripheral surface thereof; and applying operating pressure to force resin into said cavities at a mould gap defined adjacent the peripheral surface of the mould roll, to form said fastener elements, while supporting the mould roll with a support member on the side of said mould roll generally opposite the mould gap, the support member arranged to apply a force to the mould roll along its peripheral surface for resisting radial deflection of the mould roll caused by said operating pressure, to maintain the mould gap at a desired thickness profile across the width of the base web under said operating pressure. The use of the fastener elements to secure pipes in position is not disclosed.
In GB1196655 there is described a fastener comprising a pair of inter-engageable articles each having a base from which project a multiplicity of spine-like elements, each comprising an enlarged head at the end of a resiliently flexible stem, the heads being unordered, so that when the articles are inter-engaged a majority of the element heads of each article are held beneath the element heads of the other article over the area of engagement. The fasteners can be fabricated by injection moulding, compression moulding, progressive stamping and die forming, casting, investment moulding, embossing, vacuum forming and flocking. The use of the fasteners to secure pipes in position is not disclosed.
In JP59078825 there is described a light-weight cable in a stable flocked state that is obtained by a method wherein a synthetic resin pipe is widened from a cut-out part in the axial direction thereof to effect flocking through electrostatic processing, and the widened part is then restored to the original pipe state. The use of flock coating to produce a fastener element is not disclosed.
GB 1141489 describes a method of providing flat or shaped surfaces with a flock coating, comprising first providing the surface that is to be coated with an adhesive coating and then applying fibres of synthetic or natural material which have been cut to appropriate lengths and which are to form the flock coating to the adhesive coating, characterised in that the fibres are introduced under pressure into a closed container in which the fibres are dispersed to a distribution resembling a cloud by intense agitation generated by an oscillatably suspended or irregularly moving element, a blast of compressed air through a chamber communicating with said container then blowing the fibres entering said chamber past a member located in the chamber and maintained at a high potential, and through a deflector onto the adhesive coating previously applied to the surface, which is at earth potential, of the object that is to be coated. The use of flock coating to produce a fastener is not disclosed.
The entire disclosures of all the abovementioned patents are incorporated herein by reference for all purposes.
There is an unfulfilled need for a more versatile fastener system adapted to secure a pipe in an assigned location on a support, that is quick and easy to install, can be readily assembled and disassembled and can be used with a variety of support surfaces.